one women, two men, her husband the air force captain. and the staff sergeant. her rendezvous man. >> he was a playboy, himself. >> one man too many. until suddenly there was one man left. >> it wasn't like bang, bang, bang. it was like bang, pause, bang, pause. >> which sounds more like what? execution? >> you could take it that way, yes. >> a cold-blooded killing. who pulled the trigger? did jealousy drive someone to

murder or did she? >> michelle was brilliant, cunning, ruthless woman. >> three lives lost in a deadly triangle. on the surface, high school sweethearts seemed like the perfect match, both were bright and ambitious, but if you dug a little deeper, you'd find that marriage was anything but perfect. with marti deployed for months at a time, michelle had developed a wandering eye. just how far would she go to satisfy those desires? here's keith morrison. >> what was she thinking? when she went to the computer? when she typed in those five little words? did she not understand where those little words might lead?

>> where are you at? okay. what's your name? >> michelle. >> michelle was no doubt about it dissatisfied. here she was young, successful, attractive and, yet, wasn't exactly boredom eating at michelle. she started a new career as a psychologist offering counseling new couples. >> she was relatively new with her life. i think that was her first real job. >> michelle would have laughed at the idea that pretty soon now evens would propel her to such notoriety that newspaper reporters like melissa stoddard diaz would be poking around in her past. >> michelle, from everyone i've spoken to, wanted to be somebody and really worked hard to get to we ultimately got her degree and became a professional. >> then michelle even at an

early age always seemed confident about getting what she wanted. she was just 16 when she started dating marty. marty was a couple of years older, worldly, bright, friendly, had big plans. he wanted to be an astronaut. he went to the air force academy. ♪ she was 20 when she married him at the academy's famous chapel outside colorado springs. >> marty, you may kiss your bride. >> this was back in 1991 when marty was all she ever wanted. long before she talked to that psychologist, agreed to record for the record her thoughts she'd have to overcome and her days with marty, of course. >> we did everything together. he treated me really well. i thought we had the perfect relationship. we were best friends. >> he was the dashing young officer back then. she his lovely bride. the future she imagined an endless honeymoon in which

marty's air force career would take them to exotic destinations all around the world. she just didn't imagine that world would be unromantic air force outposts in oklahoma and alabama and florida, to finally fayetteville, north carolina. they came here in 1999. marty was captain theer by them, flew one of those huge c-130 cargo planes. all that time alone, not so easy on a marriage. as she revealed during those tape recorded interviews with psychologist dr. debby leighton. >> michelle talked about a few problems in the marriage. primarily growing apart over the years. marty was away for extended periods of time. she had a hard time with that. it was getting difficult for her. she was lonely. >> sometimes he was gone for months and when he finally did come home, military families have come to know that adjustment period all too well. they bickered, they argued about

her housekeeping, his job, about having children. he wanted them, she didn't. she was worried she'd be stuck raising them by herself in a town where she was already miserable and lonely. >> fayetteville, loserville and had nobody to hang out with, nobody i could pick up the phone and call. >> that actually is about the time it started. harmless really. just a few key strokes. see what might happen. goes on all the time these days on the internet. sexy brunette seeks rendezvous man. and before long, her internet inquiry got a response. from him. the name was john, john diamond. >> john loves women. john was a lady's man. john always had girlfriends. >> so debby, john kid's sister, could certainly see her brother responding to a solicitation like michelle's. >> my brother has a great personality.

he's an attractive guy and, you know, his personality makes him that much more attractive. >> then a few days after meeting online, they met in person at a local restaurant. >> he was charming, he was funny. movies and music and things we talked about. >> he was an army sergeant, trained at ft. bragg, trained as a sniper, highly decorated. >> he was a great soldier but he was a playboy, himself. he had been married once before and had a child from his first marriage and he left the first wife and married and they had a son together. >> michelle didn't know that john was still married. but maybe it didn't matter. at least not then. she loved the sex. the attention. the excitement. >> he was very sensitive, he was very affectionate, he was very adoring.

yes, felt great. >> i think it was just the sex. that's what he was obsessed with. he was smitten with having sex with her. >> for michelle, well, it was more lust than love. >> she felt that the affair did not take away from the fact that she loved marty. she said he was the love of her life and that she never loved john diamond. >> marty, he was in the dark, of course. when michelle told them their marriage was in crisis and they needed to see a counselor -- >> he wouldn't agree with counseling and i moved out. he was shocked. >> michelle got her own place and spent much of that steamy fayetteville summer with john diamond. >> he was so -- >> diamond was nuts about michelle, never met anyone like her before. >> she challenged him ways he'd never been challenged before. >> paul wolverton is a reporter with the "fayetteville

observer." >> she was strong and intelligent and exciting for him. >> but was he enough for her? apparently not because after three months on her own, michelle went back to marty. >> she felt that the marriage could survive, despite everything that has happened. that they could make it. >> so john and michelle's six-month affair seemed to be off. then a few weeks later it was apparently back on. the two traveled to the tropical island of saba, where michelle interviewed for a job at a local university. later that fall a romantic rendezvous at a raleigh hotel where they celebrated michelle's 30th birthday. michelle, as she would later tell the psychologist, insisted it was just a relapse. >> i knew that i loved marty and i knew that i wanted to make it work. in my heart. >> but john diamond was devastated.

or so said michelle. >> he said specifically i'm going to kill myself, i can't live without you, you can't do this to me, i'm going to go drive my car off a bridge. >> it was awful, said michelle. diamond kept calling, made a scene at her office in front of some students she taught. even threatened to call marty and tell him everything. so nearly a week after that romantic night in raleigh, michelle says she met john at a local restaurant to end the affair. gently, but for good. >> we had the whole talk. be friends. and this can never happen again never, never, never. he was very calm, very rational. >> now it was december. time for peace and joy and christmas parties. one in particular at which the spirits flowed and the feud burned down to its explosive end. somebody was about to die.

and somebody else wasn't taking any chances on missing. >> it wasn't like bang, bang, bang. it was like bang, pause, bang, pause. >> sounds more like what, execution? >> you could take it that way, yes. >> when "deadly triangle" continues. hen "deadly triangle" continues. geico makes it easy to get help when you need it. with licensed agents available 24/7. it's not just easy.

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here again is keith morrison. >> here in the heart of the american bible belt, on the fringe of vast sprawling army and air force bases, like a patient accommodating land lord, is fayetteville, north carolina. imagine, most of a suburban strip mall of strip clubs and a downtown which is charming, elegant even, and a scene about everything. it's an old town, fayetteville. that tower marks the spot where north carolina ratified the federal constitution back in 1789. i'm standing on what was a slave market. sherman fought battles here in the civil war. now it's a military town and

160,000 acres back there is the army's ft. bragg where soldiers prepare to go to war. nestled up beside that is the air force base. two institutions, two professional military men, one woman. and that woman, michelle theer, now found herself caught between her husband, marty, the air force captain and her former lover, army staff sergeant john diamond who just wouldn't go away. >> i told him, i don't want to leave my husband. i never told him, i love you, i never said, i want to be with you. i mean, i think i was pretty straight up. >> now with the holiday season at full swing and a new commitment to her marriage, michelle and marty were on the road to raleigh, for a night out. traveling with them was another couple from her office. >> they had gone to this christmas party that she specifically asked her boss if marty could go. >> it was the date for office party standards and early morning since marty had to fly early in the morning. marty, michelle and the co-workers prepared to leave the restaurant. then an interruption. michelle excused her. made a brief phone call out of earshot of the others.

then the drive to fayetteville. one hour. they dropped the other couple at michelle's office then left for home. stopped on the way for gas. and then sitting at the gas pump, michelle told marty she'd forgotten something at the office. >> turning around and going back to the office to get some stuff that i needed so i could stay up and work that night. >> marty, parked behind the office building. michelle walked up an outside staircase, disappeared inside. marty, waiting in the car. apparently he got impatient, headed up the stairs to check out michelle. and that's when it happened. [ gunshots ] she found him, she said, at the bottom of the outside doorway. she could see the blood. she ran to the nearest store,

called 911. >> somebody's shot? somebody shot your husband? >> i think so. >> where are you at? okay. what's your name? >> michelle. >> within minutes fayetteville police and paramedics arrive and find michelle cradling her husband in a pool of blood, but it was too late. marty theer was dead. he was just 31. because marty was an air force captain, military investigators were soon on the scene as well as police. a joint investigation with the fayetteville pd. both teams were eager to speak to the only known witness, michelle theer. officers special investigations unit, vince -- >> she said what sounded like her three bangs of a car back firing. >> did she say what she did at that point? >> she opened the door and saw her husband laying at the bottom of the stairs. >> she thought she saw someone moving in the bushes. >> initially police were looking

at perhaps a robbery of some type. >> detectives combed the parking lot's surrounding area but found no one on this cold, dark december night. >> there was a man who lived behind the office building who heard the shots fired who later said that he said, somebody's getting murdered out there. because of the order in which the shots were fired. they were very calculated. >> it wasn't like bang, bang, bang. it was bang, pause, bang, pause. >> which sounds like what? an execution? >> you could take it that way, yes. >> at the top of the stairway were a few clues. bullet holes sprayed in the wall. sequins littered. he was at the top of the stairs shot from down below. >> i think that's what made him roll down the stairs and the final shot was to the back of the left ear.

>> the kill shot. >> the kill shot. close range. >> they found shell casings in the parking lot. appeared to be from a .9 millimeter handgun. but there were no fingerprints. no footprints. no useful dna. investigators did find marty's wallet. still on him. complete with cash and credit cards. >> marty theer was not robbed. the other thing that was a very, very cold night. not a night where a prowler would be out on the streets just looking to find someone. it made it very suspicious. >> investigators couldn't imagine who would want to kill such a wonderful man like captain marty theer. but of course, out on this dark parking lot they didn't know any of what you know. not yet anyway. assuming what you've heard so far is the real story. and as you'll see, the question

of what was true and what wasn't could be very tricky indeed. coming up, michelle said she'd gone back to her office because she'd forgotten something. so what took so long? >> they found a candy wrapper that had been opened in the trash can. it was almost like a thing where she'd gone upstairs and sat and waited for a few minutes. >> for what? when dateline continues. when dateline continues. we got the idea that if we took two dimensional patient imaging and put it in holographic displays, we could dissect around the tumor so we can safely remove it. when we first started, we felt like this might just not be possible but verizon 5g ultra wideband will give us the ability to do this. ♪ (burke) at farmers insurance, we've seen almost everything, so we know how to cover almost anything. even a parking splat.

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welcome back. he was gunned down outside his wife michelle's office. it was michelle who called 911 saying she thought she'd seen a dark figure hiding in the bushes. to police, it looked like a targeted hit and they were about to discover michelle had a secret. could marty been in a love's triangle. we're again is keith morrison it was a week before . christmas, 2000, and fayetteville was aglow, but not everywhere with the lights of christmas. and a few hours after air force

captain marty, theer turned up dead in the parking lot of his wife's office building, the news was out and it was big. michelle theer, now marty's grieving widow, told the police she was inside her office looking for a book when she heard someone firing outside. >> by all counts it was an assassination. >> greg buckner was a deputy district attorney at the time. >> someone would kill marty theer, that night, no evidence of robbery, no evidence of any other thing going on here. >> inside michelle's office, what they found seemed, well, a little odd. maybe. >> she'd gone to the bathroom. the toilet had not been flushed. they found a candy wrapper opened and in the trash can. it was almost like a scene where she'd gone upstairs and sat and waited for a few minutes because obviously to find a book wouldn't take very long.

>> strange. hard to know what it meant, if anything. as dawn approached, michelle was allowed to go home. and later that morning, her boss arrived. so the cops talked to him, too. >> during that interview it came out she was having marital problems and was having some affairs. >> funny. michelle hadn't mentioned anything about that. so detectives went to her house to follow-up. and sure enough, michelle did admit having an affair with staff sergeant john diamond. michelle also said she hadn't spoken to diamond in two days. but when pressed, she remembered trying to call him unsuccessfully just before leaving that christmas party. 90 minutes before marty was murdered.

detectives decided to check their cell phone records and discovered -- >> they've been calling each other regularly, minimum 20 times a day. >> now detectives paid a visit to john diamond. who freely admitted having a sexual relationship with michelle. but claimed she was just one of many ladies in his life. and as for the night of the murder, he had an alibi. he was home with his family. watching a movie. still, michelle must have harbored some sort of suspicion about john diamond who was now a person of interest. not long after the murder, as she told detectives and that psychologist, she went to see diamond, conduct her own investigation. find out what he knew about marty's death. >> if you know anything about this, you know anybody who had anything to do with this, please tell me. i would never do anything to hurt. i know how much you love -- >> mind you, as police were soon aware, michelle had many opportunities to question her friend, john, after her husband died. >> witnesses said he parked down a little side street then walked through their yards going through the back door of her

house. >> he couldn't stay away? >> going through, staying all night. >> not commonly the way widows grieve, spending the night with the person of interest in her husband's murder. michelle told psychologist dr. deb by leighton she needed support from someone, anyone. >> she felt more alienated from family and friends and more threatened by the police. the only person in her life that was willing to be there for her was john diamond. >> i was getting more and more depressed. i went to john for comfort. >> a few weeks after marty's murder, michelle and john drove to florida for a long weekend. michelle wanted to see a former professor for grief counseling, she said later. while diamond stayed with his sister, debby. >> he acted as if nothing was wrong. he knows he didn't have anything to do with it. he didn't shoot him. >> how did kill captain marty theer? is it possible john diamond

executed his romantic rival? he may have had a motive. police were very suspicious. but the physical evidence was, frankly, rather weak. so detectives kept digging in the arcane world of phone records. boring, but sometimes revealing. and one telephone number in particular caught their attention. a call from diamond to one of his army buddies at ft. bragg. >> so we asked them if diamond had any access to any weapons. he said that he loaned diamond his personal pistol. >> which just happened to be a .9 millimeter berretta pistol, the same kind of gun that killed marty theer. >> john diamond had actually borrowed the gun from him during the timeframe when the murder occurred, john diamond had possession of it. >> detectives were convinced diamond not only had access to a gun, but maybe even the actual

murder weapon. did he still have it? well, apparently not. because just a short time after cops went to the home of diamond's army buddy asking about that gun, diamond made a phone call to ft. bragg and reported that his car, which he claimed to have left in the base parking lot, had been broken into and one of the things stolen from it was a .9 millimeter handgun. >> when we got there the passenger door had already been open and there was a pile of glass sitting next to the rocker panel on the passenger's side. if you look on the inside, there was very little glass. >> what did that tell you? >> he had the door open when he broke the window and then tried to make it look like it was broken in. >> a bogus break-in? military police sure thought so. john diamond was arrested for admitting he brought an unregistered gun on base. diamond was now the prime suspect in the murder of captain

marty theer, but was he really the killer? coming up, a secret about john and michelle's steamy affair becomes very public. >> she was taking him to these sex clubs and saying, it's okay, go, you know, if you want to have sex with her, that's fine and he just, wow, okay. >> when "deadly triangle" [ ding ] -oh, i have progressive, so i just bundled everything with my home insurance. saved me a ton of money. -love you, gary! -you don't have to buzz in. it's not a question, gary. on march 1, 1810 -- [ ding ] -frédéric chopin. -collapsing in 226 -- [ ding ] -the colossus of rhodes. -[ sighs ] louise dustmann -- [ ding ] -brahms' "lullaby," or "wiegenlied." -when will it end? [ ding ] -not today, ron. woman: (on phone) discover. hi. do you have a travel card? yep. our miles card. earn unlimited 1.5 miles and we'll match it at the end of your first year. nice! i'm thinking about a scuba diving trip.

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the latest charter school scandals are piling up. leaders of one san diego charter network? indicted for conspiracy and grand theft. thankfully, the governor's charter school policy task force just made important recommendations for reform: more accountability on charter school spending. and giving local school districts more control over the authorization of charter schools. reforms we need to pass now. so call your state senator. ask them to support ab 1505 and ab 1507.

our top stories, president trump is expected to impose new sanctions on iran on monday. the sanctions come days after the president backed off a plan for airstrikes following a u.s. navy drone being shot down by iran. pete buttigieg faced a hostile hometown crowd on sunday a the a town hall meeting. he appeared a week after shooting of a black man by a white police officer. now back to "dateline."

welcome back. i'm craig melvin. john diamonds of the prime suspect in the murder of marty fear. he was having ab affair with michelle and was arrest eed admitting he brought a weapon on to the military base. but investigators wondered if he was the shooter, could someone else have been the master mind behind the crime. here again is keith morrison. >> a few weeks after the murder of captain marty theer, well, police chased more earthbound clues. a fayetteville police detective named c.t. williams was asked to have a look at a couple of computers seized from michelle theer's home. see if they might contain any clues.

>> i was looking for documents or text messages or e-mails. >> like an onion he peeled book the layers of texts which though they'd been deleted reappeared under his expert touch. boxes of deleted documents, 88,000 of them, buried deep inside michelle's hard drive. and out spilled some of michelle's most intimate sexual secrets. >> she seemed to be seeking affairs with a number of people over time. she was looking for an alternative lifestyle. she was seeking a partner escort for sexual clubs. >> that would be carolina friends, a swingers club. it boasted more than 10,000 members. and within michelle's lengthy list of e-mails detectives also discovered that not so innocent inquiry she typed seeking a rendezvous man. that was john diamond, of course, who replied and who the e-mail trail revealed quickly joined michelle in the

lifestyle. >> she was taking him to these sex clubs and saying, it's okay, go, you know, if you want to have sex with her, that's fine, go, i'm fine with it. and he just, wow, okay. >> but as investigators sorted through the sexually charged e-mail, they could plainly see a story as old as time. john diamond fell head over heels in love with michelle. >> he was her little puppy. to be controlled any way she wanted to control. >> he was like the child in the relationship. >> whatever she wanted, he was at her beckoning call. >> hundreds upon hundreds of love-sick e-mails. john diamond appeared to be a map obsessed. i can't wait until you come back so we can take care of each other. you know, sex, sex, sex and of course, more sex. i know that we're meant to be together and are kindred soulmates. i will always love you, no matter how you've hurt me. >> you can tell it changed from a sexual relationship to a completely, totally enamored with her any way you can imagine. >> he was gets desperate. >> he wants to be with her. he was willing to do anything. keep the woman he's totally in

love with. >> anything? perhaps even kill the man who stood between him and michelle? >> she was beginning to set him up. she's playing to his emotions. she was pushing him away. push him away in some ways but without completely pushing him away. >> push/pull. >> she was manipulating him at that point. >> manipulating him into murdering her husband? why would she want to do that? >> there was a $500,000 life insurance policy taken out in 1999 on marty theer. >> the sole beneficiary? michelle theer. john diamond's family was outraged at such a theory. they were convinced michelle typed all those e-mails and sent them to herself to steer investigators away from her and to diamond. so he'd take the raft. >> he never once expressed a love feeling about her to me. unless you come to me with handwritten letter that he was obsessed with her, i'll never believe that.

>> how do you know that? >> because he told me. he did not want to marry her. he did not want to spend the rest of his life with her. >> according to debby, it was michelle who was obsessed with john. and never more so than when she gave debby two wedding rings to take to her brother who was by this time locked in. >> i think she was obsessed with him to the point she couldn't control him, she couldn't, you know, control the situation. >> she wanted to control it and if she gave him a wedding ring and he wore it, wouldn't that give her all kinds of reason to claim that he would do anything for her? including kill her husband? >> that could be. i don't know. what i got from him after he was arrested was he didn't want anything to do with her. nothing. >> with or without michelle, john was in big trouble. so he lawyered up with prominent fayetteville attorney, clay brewer. >> i believe that he was an

innocent man wrongly accused. that any rational interpretation of the circumstantial evidence is consistent with sergeant diamond not being the shooter. >> but military investigators were convinced diamond was the triggerman and decided to quickly proceed with their case against him. and michelle, to remain free. and what did she do? she left town. >> i think she planned to kill her husband a long time ago. i think she waited and researched and waited for that right person that would look and fit the part to pin it on. >> if that was true, michelle's plan was working perfectly because in a few short weeks john diamond would be on trial for murdering her husband. coming up, the prosecution's case against john and the defense's case against michelle. >> michelle theer was a brilliant, cunning, ruthless woman who wanted her husband dead.

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save at trelegy.com bhavr the truth, they left toin leaving john to face trial alone. but she would not be gone for long. here again is keith morrison. in the dead center of ft.

bragg, north carolina, is a nondescript red brick building, this is where army staff sergeant john diamond found himself a prime suspect in the murder of air force captain marty theer. >> military justice is much swifter than civilian justice. so he goes to the article 32 hearing which is like the grand jury. they immediately find cause and they charge him. >> and nine months after the murder, in a small ft. bragg courtroom, diamond went on trial before a military jury. >> diamond was very, very cocky at the beginning. he would laugh and joke with reporters in there. he was just so sure that he was going to be acquitted. >> john diamond wasn't the star of his own trial. michelle was. she was free as a bird then. though still under investigation by fayetteville civilian homicide cops. and here she was called to testify at her former lover's military trial. >> she shows up, her hair is now, like, a red color that she's colored it.

she's lost a bunch of weight. and she's got a gaggle of media following her into the building. >> it was all image. no substance. michelle took the stand but took the fifth. the prosecution's case against diamond, its accusation was simple. driven by his obsession for michelle, he conspired with her to kill her husband by borrowing the gun, arranging to be in a position in that dark parking lot, waiting until marty theer had placed himself in the kill zone at the top of the staircase outside michelle's office. and fired the five shots that killed him. as for diamond's alibi that he was home with his wife watching a movie, that now ex-wife came to court and told the jury that the evening wasn't quite like that. half way through the movie his phone rang, she said and suddenly he was gone. what's more? >> her mother heard him come home, you know, in the wee hours and wash clothes. >> true?

maybe not said defense attorney brewer. her story changed after she talked to police. >> she was afraid of the government. i don't think that she was telling the truth. >> had she been pressured? besides, said the defense, there was no dna. no footprints. no fingerprints to prove diamond shot marty theer. diamond was a trained shot shooter but the ones that hit marty were mostly badly aimed, must have been a work of an amateur, said the attorney. someone like michelle. >> michelle asked for the gun several days before the murder, told him her husband was a beast and was afraid of him. he gets the gun and gives her the gun. he didn't think she was going to use him for the gun. >> did she use him? somebody she could use to serve his purposes? >> she set this up to kill her husband because she wanted the insurance money and for sergeant

diamond to take the fall. michelle theer was a brilliant, cunning, ruthless woman who wanted her husband dead. >> the military jury, however, didn't see it quite that way. >> the verdict was swift. guilty as charged. and from that moment on, his demeanor changed. i mean, it was, like, somebody just sucked the air out of him. the john diamond full of bravado and ego just shrivelled away. >> diamond was sentenced to life in prison without parole. his family was furious, convinced he was framed. >> you don't expect to be convicted on theory and myth and what ifs. show me blood, show me a gun. show me the timeline that works. show me those facts. i'll believe until the day i die

that she killed her husband, that she planned to have my brother go down for it so she could live this happy, wonderful life. >> curious thing that. john diamond settled into a life in prison, people around fayetteville could see to their great disapproval that michelle went on with a life uninterrupted. then quite suddenly they didn't see her at all because michelle theer disappeared. >> she was also now a wanted woman. coming up -- >> there's some speculation that she was ticked off that she had been indicted because she seemed to really sort of fall off the face of the earth. >> when "deadly ambush" continues. continues. ♪

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welcome back. air force captain marty sheer

was dead. investigators uncovered a digital treasure-trove from michelle's computer revealing a steamy affair with john diamond. soon authorities would want to talk to michelle about her involvement in the crime. but first they would have to find her. with the conclusion of our story here pf here's keith morrisson. >> federal prison, doing time doesn't come much harder than it does here. this is where john diamond was now serving a life sentence for murdering air force captain marty theer. but his former lover, michelle, seemed to have dropped right out of sight. where was she? people weren't seeing her around fayetteville. the d.a., meanwhile, was convinced she must have conspired with john diamond to kill her husband. she was the brains. he was the brawn. or in this case, the shooter.

though it was all circumstantial, said greg butler, it was persuasive. >> there was evidence, there's no question as to who was involved. diamond and her together. >> the evidence? a life insurance, the affair, the access to a murder weapon, those e-mails, the cover-up. taken together, it was enough to convince a grand jury. and finally, in may of 2002, nearly 18 months since her husband was killed, michelle theer was indicted for first-degree murder and conspiracy. but arrested? no. why? >> there's some speculation that she was tipped off that she had been indicted because she seemed to really sort of fall off the face of the earth right before that came down. >> michelle theer vanished. no one, not even her family, knew where she was. lauderdale by the sea is a charming little town, just north

of miami. quaint and quiet. low profile. in the summer of 2001, cindy geasy, a local landlord, met with a woman who wanted to rent a room at her cottage. >> she gave her name as liza, i let her sign a six month lease. she told she she was on the run from an abusive boyfriend in california. >> she made friends around the neighborhood. before long she had a new beau. liza, it was really michelle, of course, kept in touch with her family very carefully. secretly. she only called on pay phones, for example. and that rarely. two months after michelle arrived in florida, she asked her boyfriend to call her parents, pass on a message, use a pay phone, she told him. and maybe he forgot or perhaps she didn't tell him why, but he called from his parent's house phone. u.s. marshals were monitoring. they looked up the number that

had called michelle's parents. >> the database told them this woman had a son in his mid 20s who lived in south florida. >> did he know the missing michelle? the cops found him, staked him out. then followed him to that little white beach cottage. where he and michelle were in for a big surprise. >> following a developing story out of florida. a woman wanted for the murder of her husband has been arrested in florida. >> at the time of the arrest inside her apartment we found magazines describing ways of how to go undercover in the united states, obtain new identity. >> books on learning spanish, travel guides for latin countries, an array of fake i.d.s. then there was michelle's appearance. >> she had changed her appearance. cut and dyed her hair. had plastic surgery done.

>> anything at all to say? >> a few days later, michelle her face swollen and smeared with ointment from cosmetic surgery, was driven back to fayetteville. she was charged with first-degree murder and locked up without bail. and two years later, in september 2004, after turning down a plea deal that would have imprisoned her ten years, the prosecutor laid out his case against michelle theer. the proof, for one thing all those e-mails would show, said the prosecutor, how michelle manipulated diamond into a fatal frenzy and made him her fall guy. >> she got -- he was so upset if he couldn't have her he was going to kill himself. if you're willing to kill yourself, it would not take much now to redirect that and kill someone else. michelle directed him, it got to

the point where he was willing to kill marty. >> that point arrived, said the prosecutor, after the office christmas party when michelle called diamond to tell him that she and marty were heading to the kill zone. the parking lot of her office building. but she needed him there alone. so after they dropped two co-workers at the lot, said the prosecutor, michelle made a crucial move that inextricably linked her to the murder. remember, the theers began driving home, stopped for gas. michelle by her own admission had marty return to the office supposedly to pick up some work she needed. and while she dawdled in the office, marty became impatient, went up those stairs to check on her. and thus walked into an ambush. >> when they left, there was in no way for that shooter to have any reason to believe they were coming back unless he had known through prior conversation michelle theer. he was going to bring him back to that location, go up and do her business, leaving him outside the door so he can then murder her husband. >> that was really your smoking gun. >> that was the smoking gun that tied her to it. >> michelle did not testify. nor did john diamond.

her attorney belittled the state's evidence as thin and circumstance. among those speaking for michelle, psychologist debby leighton. she was hired for the defense to interview michelle about her relationships to testify as an expert witness. those were the recorded conversations, excerpts of which you heard earlier. the doctor told the jury michelle wasn't manipulating diamond by stopping and starting their illicit romance. no, it was something else. >> when somebody's in a long-term affair, there does tend to be a pattern of pulling away and then coming back together. an inability to be decisive. that's not unusual with affairs. >> besides, claimed the defense, being involved with another man didn't mean michelle was also involved in murder. the two sides battled through three months of trial time. from labor day past thanksgiving. 11-week trial. three-hour deliberation.

the verdict? guilty. >> she stood up. they put the handcuffs on her and she walked out the courtroom and she never looked back into the courtroom area. not even toward her family. >> michelle theer now sits in a north carolina prison, half way across the country from her co-conspirator, john diamond. the former lovers share one thing, life without parole. >> his supporters are heartfelt in their certainty that she was the bad one. she did it all. he didn't do anything. >> her supporters all blame him and say he did it without her knowledge because he was in love with her and she was breaking up with him. >> michelle theer rolled the dice. she turned down a deal which would have released her before long. instead, the woman who followed her dissatisfaction to an internet romance went on trial.

and as a result will die in prison. >> that's all for this edition of dateline extra. i'm craig melvin. thank you for watching. i can't believe that your baby's lying there lifeless. >> she was everything to me. she was so sweet to everybody. >> state troopers said bonnie had died in a hiking accident. >> they said she fell off a cliff. her mother said they were wrong. >> i was screaming to them, these are defensive wounds. >> no witnesses, no weapon, nothing left behind but a